The majority of families experienced a sustained rise in living standards through the 1970s and 1980s.
The plan pays bonuses to the executives for each $10 sustained rise in the stock over the $25.5625 level.
More importantly, analysts said a sustained rise in hours worked often led to an increase in employment.
In 2006, the sustained rise in oil prices had only a limited impact on demand.
He added: "It is hard to see any sustained rise in prices until the uncertainty dissipates.
As for the lake itself, the levels dropped markedly until 1862, then once more began a sustained rise.
They are even talking about a sustained rise in employment.
And a sustained rise in the cost of energy could substantially slow economic growth.
Clear signs of a sustained, widespread rise are still scarce.
"The real risk to the stock market is a sustained rise in interest rates."